Flush-type latch



Jan. 18; 1955 J. E. HOGAN ETAL 2,699,952

FLUSH-TYPE LATCH Filed' Jan. 11,1951 2 sheets-snee: 1

' 52 3/ 29 525030 44 |NvENToRs. vlo/w E HOGAN, :El |3 4L Mszoo/v/Q/vfncn' ra/ATTORNEYS Jan. 18, 1955 J. E. HOGAN ErAL FLUSH-TYPE LATCH 2Sheets-Sheet 2 Filed Jan. l1 1951 IF/Av/IIIIIIIIIIIIIIIIIJ r.rllllllllllllllllll,

' v l l'. I f

IIIIIIIIIIIIII lill 15:15 /Jf J/)4 INVENTORS.

Arron/ve ys JOHN E. Haan/v United States Patent() FLUSH-TYPE LATCH JohnE. Hogan, Los Angeles, Calif., and Weldon R. An-

drews, Seattle, Wash., assignors to Clark Hartwell and Eleanor M.Hartwell, both of Los Angeles, Calif., doing business as HartwellAviation Supply Company, Los Angeles, Calif.

Application January 11, 1951, Serial No. 205,552

6 Claims. (Cl. 292-108) This invention relates to a flush-type latch,and more particularly to a Hush-type latch of the lever operated type,especially adapted for a closure for pressurized cornpartments ofaircraft.

In modern, high-speed, high-altitude aircraft, it is common andnecessary to provide pressurized compartments and cabins and it is alsonecessary that the various openings leading into the compartments beprovided with latch mechanisms, which not only positively insure thecompartments against accidental opening, but in which the latches areflush with the surface of the outside of the aircraft, thus reducingfriction loss at high speed. It is also necessary that the doors to suchcompartments be provided with a substantially airtight seal.

It is accordingly one object of this invention to provide a ush-typelatch of the type described which provides an airtight seal.

It is a further object of this invention to provide a flush-type latchof the type described which has secondary means insuring againstaccidental opening.

It is a still further object of this invention to provide such ailush-type latch of the lever operated type in which not only theprimary latching lever assumes a flush position in latched condition,but in which a secondary lever also assumes a flush position in itsdogging position.

These and other objects and advantages of the invention will be apparentfrom the annexed specification in which:

Figure l is a plan view of a closure provided with a flush-type latchembodying the present invention with parts broken away for clarity ofillustration;

Figure 2 is a section taken along the line 2 2 of Figure 1;

Figure 3 is an enlarged section taken along the line 3 3 of Figure 1;

Figure 4 is a section taken along the lineKL 4 4 of Figure 3;

Figure 5 is a side elevation of a ush-type latch embodying a modicationof this invention;

Figure 6 is a section taken along the .line 6 6 of Figure 5;

Figure 7 is a section taken along the line 7 7 of Figure 5;

Figure 8 is a section taken along the line 8 8 of Figure 5;

Figure 9 is a perspective view ofthe auxiliary latch member.

The numeral 10 represents a plate such as the outer skin of an aircraftor the like having a preferably rectangular opening 11 therein. A plate12, having a smaller rectangular opening 13, is provided and ispreferably riveted to the plate 10 with a cork seal 14 interposedtherebetween. The plate 12 and the superposed cork seal 14 extendsinwardly on all sides from the edges dening the opening 11 in the plate10, as indicated at 15. The plate 12 is provided adjacent one endthereof with a pair of openings 16 and 17. Aligned with each of theopenings 16 and 17 and aflixed to the plate 12 on the rear side thereofare a pair of depending wells 18 and 19. Each of the wells 18 and 19 isprovided with side walls 20, an end wall 21, and a sloping end wall 22.The edges of these walls are turned outwardly to form a flange 23, whichilange 23 is riveted, as at 24, to the bottom of the plate 12 with acork seal 25 interposed between the plate 12 and the ange 23 to form anairtight seal.

Each of the wells 18 and 19 is also provided with a 2,699,962 PatentedJan. 18, 1955 pair of transverse pins or rods 26 and 27. Each of therods 26 is disposed across the well toward the upper end thereof andeach of the rods 27 is disposed across, the Well toward the lower endthereof, and the pins or rods 26 and 27 may be attached to the sidewalls 20 by rivets 28 and 29 driven therein through apertures 30 and 31in the side walls.

A closure plate 35 is provided, preferably formed of two sheets 35a and35b spot welded together and having riveted thereto adjacent the loweredge thereof a plate 36. The plate 36 has a V-shaped channel portion 37and a marginal flat ange 38, as clearly shown in Figure 2. The plate 35is adapted to be placed with its edges conforming to the inner marginsof the opening 11 and with the flange 38 of the plate 36 extendingbehind the lower margin 39 of the plate 12. The plate 36 thus forms ahinge or hook for the plate 35 which also permits complete removal ofthe plate 35 from the closure. The plate 35, toward its upper end andtoward its sides, is provided with a pair of slots or openings 40 and 41adapted to register with the openings 16 and 17, respectively. The underside of the plate 35 is recessed on either side of the slots 40 and 41and toward the upper end thereof by cutting out a portion of plate 35bin order to permit the flush reception of the ange 42 of a channelshaped member 43. The anges 42 are riveted to the under side of plate35a as at 44. Channel shaped member 43 has the bottom thereof cut out asat 45. Pivoted in the walls of the channel shaped member 43 adjacent theupper end thereof is a latch bar 46.

The latch bar 46 is channel shaped and toward its upper end is providedwith a latching member or hook 47. In constructing the hook 47, twoC-shaped pieces 48 and 49 are preferably spot welded together to form aunited member and side plates 50 and 51 are also spot welded thereto.The members 48 and 49, 50 and 51 are bored upon a common axis andsecured to the walls 52 and 53 of the channel member 46 by means ofhollow rivet 54. The hollow rivet 54 also forms a bearing upon which thelatch bar 46 pivots. The side plates 50 and 51 have extensions 55 and 56forming stops for the upper end of the auxiliary latch hereinafterdescribed.

As' shown in Figure 3, the hook 47 is adapted in one posltlon to engageunder the pin 26 and latch the closure 1n closed position and, inanother position, to dsengage the pin 26 for opening of the closureplate.

The latch bar 46 has a longitudinal rectangular opening 57 formedtherein and, pivoted from the side walls of the latch bar by means of apin 58 is an auxiliary latch member 59. The auxiliary latch member 59has an upper surface 60 adapted in closed position to be flush with thesurface of the latch bar 46 and is itself channel shaped m crosssection, having two side walls 61 and 62. The side walls 61 and 62 arecontinued downwardly and provlded with extensions forming a hook 63adapted to engage the pm 27. The side walls 61 and 62 are contmuedbeyond the forward limit of the top surface 60 as at 64 to formprojections adapted to engage the stops- 55 and 56 to limit the openingof the auxiliary latch 59 and also to engage underneath the edge of thetop surface of the latch bar 46, as at 65.

A coiled spring 66 is wound about the pin 58 and has.

modified form of this invention is illustrated Land wherer other partshaving the same function are designated by the same numerals. In thismodification pin 26 is removed and a pm 69 is substituted therefor, thepin 69 being retained by arms 70 and 71 which are suitably attached atone extremity to opposed extremities of the pin 69 and which, at theiropposite extremities of the arms, are secured to the plate 35 by rivets72 which pass through suitable apertures in plates 35 and 12 and throughthe flanged portion 73 of the arms 70 and 71.

This mounting of the pin 69 provides greater strength than the mountingof pin 26 in the prior embodiment.

In the prior embodiment, in the event of a force attempting, to move thelatch to the left, as seen in Figure 3, the pins 26 and 27 being mountedin the side walls 20 remain stationary so that both the primary andauxiliary latch members will disengage the pins 26 and 27 permitting thewhole latch structure to be freed.

In the modified form the pin 27 is retained in suitable apertures in theextensions 74 and 75 of the side Walls 61 and 62 instead of in the sideWailsZi of Wells 18- and 19. By thus providing the pin integral with thedoor, when a force to the left, with respect to Figure 5, is appliedupon the latch member the pin Z7 is carried with the latch so that theauxiliary latch means 59 is not unlatched by this lateral motion andcontinues to retain the primary latch means in the locked position.

The operation of the device is as foilows:

Assuming the plate 35 is in position and fully latched and it is desiredto unlatch the latches to remove or open the plate, an operator mustfirst unlatch the latches 59 by pivoting the latches about the pins 53in order to disengage the hooks 63 from the pin 27. With the auxiliarylatch thus disengaged from the pin 27, the main latch bar 46 may bepivoted to the upright position shown in phantom in Figure 3 in whichthe hook 47 disengages the pin 26. When both of the main latches havethus been disengaged, the plate 35 may be either bodily removed from theclosure or pivoted into open position.

It will be noted that it is first necessary to disengage the auxiliarylatches 59, and even With the auxiliary latches 59 disengaged, it stillremains to disengage the main latch bars 46. By this dual latchingmeans, accidental opening of the closure is prevented. This is animportant consideration in aircraft, and especially military aircraft,as it insures against the accidental opening of the closure on beingstruck by a missile in warfare. It will also be noted that despite thecomplex and dual nature of the latching mechanism, there is achieved bythis invention a completely Hush-type latch which minimizes skin effector air friction on the surface of the aircraft.

While there has been described what at present is con sidered apreferred embodiment of the present invention, it will be appreciated bythose skilled in the art that various changes and modifications can bemade therein Without departing from the essence of the invention and itis intended to cover herein all such changes and modications as comewithin the true spirit and scope of the appended claims.

What is claimed is:

1. A flush-type latch for use in a wall having an opening therein andadapted to engage a pair of pins mounted Within the opening, saidush-type latch comprising: a plate adapted to close said opening; saidwall adjacent said plate having an opening formed therein; a latchmember pivoted on said plate and movable in said opening; said latchmember having means engageable with one of said pins to latch said platein closing engagement with said Wall; said latch member being providedwith an opening; an auxiliary latch member pivoted on said latch memberand movable in said opening in said latch member; said auxiliary latchmember having means engageable with the other of said pins to lock saidlatch in latching engagement with said first pin.

2. A flush-type latch for use in a Wall having an opening therein andadapted to engage a pair of pins mounted Within the opening, saidflush-type latch comprising: a plate adapted to close said opening; saidwall adjacent said plate having an opening formed therein; a latchmember pivoted on said plate and movable in said opening; said latchmember having means engageable with one ofsaid pins to latch said platein closing engagement with said Wall; said latch member being providedwith an opening; an auxiliary latch member pivoted on said latch memberand movable in said opening n said latch` member; said auxiliary latchmember having means engageable with the other of said pins to lock saidlatch in latching engagement with said rst pin; said latch member andsaid auxiliary latch member having their outer surfaces ush with theouter surface of said plate when yin latched position.

3. A flush-type latch for use in a Wall having an opening therein andadapted to engage a pair of pins mounted Within the opening, saidHush-type latch comprising: a plate adapted to close said opening; saidplate having an opening formed therein; a latch member pivoted on saidplate and movable in said opening; said latch member having hook meansengageable with one of said pins to latch said plate in closingengagement with said wall; said latch member being provided with anopening; an auxiliary latch member pivoted on said latch member andmovable in said opening in said latch member; said auxiliary latchmember having hook means engageable with the other of said pins to locksaid latch in latching engagement with said first mentioned pin.

4. A Hush-type latch for use in a Wall having an opening therein andadapted to engage a pair of pins mounted within the opening, saidflush-type latch comprising: a plate adapted to close said opening; saidplate having an opening formed therein; a latch member pivoted on saidplate and movable in said opening; said latch member having hook meansengageable with one of said pins to latch said plate in closingengagement with said wall; said latch member being provided with anopening; an auxiliary latch member pivoted on said latch member andmovable in said opening in said latch member; said auxiliary latchmember having hook means engageable with the other of said pins to locksaid latch in latching engagement with said rst mentioned pin; saidlatch member and said auxiliary latch member having their outer surfacesflush with the outer surfaces of said plate when in latched position.

5. in a flush-type latch, the combination of: a latch member having aweb portion and a pair of depending Walls forming a channel-shaped bodymember, said web being provided with an opening therein; a hook memberdepending from said body member; an auxiliary latch member pivoted onsaid body member and movable in said opening rom a closed position to anopen position, said auxiliary latch member being provided with a hookmember; and spring means for biasing said auxiliary latch member towardsaid closed position.

6. In a flush-type latch, the combination of: a latch member having aweb portion and a pair of depending walls forming a channel-shaped bodymember, said web being provided with an opening therein; a hook memberdepending from said body member; a stop member carried on said bodymember below said web; an auxiliary latch member pivoted on said bodymember and movable in said opening from a closed position to an openposition, said auxiliary latch member being provided with a hook member;spring means for biasing said auxiliary latch member toward said closedposition; and a projection on said auxiliary latch member, saidprojection being positioned to contact said web for limiting pivotalmovement of said auxiliary latch in one direction and to contact saidstop member for limiting piv- 'otal movement of said auxiliary latch inthe other direction.

References Cited in the file of this patent UNITED STATES PATENTSGoddard et al Aug. 31, 1915 Best Aug. 5, 1947 OTHER REFERENCES

